// The static variable  is't belong to class.

#include <iostream>
#include <cstring>
using namespace std;

class A {
	public:
		A( ) {
			// [ int m_i; ]		define the varible m_i
		}
		int m_i;
		static int m_si;
};

 int A::m_si = 0;	// Global define and init the varible.

// designer
// ------------------------------------------------------------------
// user

int main( void ) { 
	A a, b;
	cout << "sizeof( a ) : " << sizeof( a ) << endl;
	cout << "sizeof( b ) : " << sizeof( b ) << endl;

	A::m_si = 100;
	return 0;
}

